Undefined index: lng in geolocation_googlemaps_link_field_formatter_view()

I don't have the time to post a patch but the $items array in geolocation_googlemaps_link_field_formatter_view() looks like this for me:

 [geom] => XXXXXXXXXXX
 [geo_type] => point
 [lat] => XXXXXXXXXXX
 [lon] => XXXXXXXXXXX
 [left] =>XXXXXXXXXXX
 [top] => XXXXXXXXXXX
 [right] => XXXXXXXXXXX
 [bottom] =>XXXXXXXXXXX
 [geohash] =>XXXXXXXXXXX 

You're doing this:
$lng = $item['lng']

Should be:
$lng = $item['lon']